Studies on Freshwater Zooplankton

The plankton community is a heterogeneous group consisting of tiny plants to large jelly fishes of over 10 m long adapted to suspension in the sea and freshwaters. Animals with feeble locomotory power and which are carried along by the moving water are called as plankton. They are divided into phytoplankton and zooplankton. The zooplankton assemblage inhibiting freshwater mostly comprise of Protozoa, Coelenterate, Rotifera, Gastrotricha, Bryozoa and Arthropoda (Battish 1992). Most zooplankton occupies the second or third tropic level of the aquatic food web as such these herbivores, carnivores and omnivores play a significant role in aquatic food webs. The minute size of phytoplankton denotes that aquatic grazers are very small and therefore there exits many steps or links in aquatic food webs which are necessary to support large carnivores such as fish. There are many studies on the zooplankton populations of tropical ponds. As zooplankton constitutes important live feed for many economically important fishes and prawns a large quantity of zooplankton is harvested daily by the aquarists from the ponds (Altaff et al 2002).